OpenNSL API Guide and Reference Manual: Class of Service Queue Configuration

Class of Service (CoS) Queue Management functions provides for translation of 802.1p priorities into internal class of service queues. It also permits configuration of the scheduling policies used by these queues

The devices supported by the API have different maximum queues, ranging from 1 to 2, 4 or 8 CoS queues. Mapping from 802.1p priorities to these queues is arbitrary. A mapping is an array of opennsl_cos_queue_t values indexed by priority.

The order of service of packets in different CoS queues is controlled by the scheduling mode and associated parameters. Weights and delays may be required in some modes. See opennsl_cosq_sched_set for more information. Not all devices support all scheduling modes. The following table describes how to configure the most common modes and combinations.

Strict Priority
Round-Robin
Weighted Round-Robin
Weighted Fair Queuing
Strict Priority and Round-Robin
Strict Priority and Weighted Round Robin
Strict Priority and Weighted Fair Queueing
Deficit Round Robin

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